Process of producing metal sheets by electrodeposition



May 27 1930. w s ET AL PROCESS OF PRODUCING METAL SHEETS BY ELECTRODEPOSITION Filed Dec. 1924 Patented May 27, 1930 UNITED STATES PATENT OFFICE HARRY H. WILLIAMS AND ROBERT G. SUMAN, OF DAYTON, OHIO, ASSIGNORS TO GEN- ERAL MOTORS RESEARCH CORPORATION, DAYTON, OHIO, A CORPORATION OF DELAWARE PROCESS OF PRODUCINGMETAL SHEETS BY ELEGTRODEFOSITION Application filed December 1, 1924. Serial No. 753,038.

The invent-ion relates to the production of metals in sheet form,particularly by the use of an electrolytic process.

Its objects are to produce strips or sheets 6 of metal of indefinite length; to produce such strips or sheets in a continuous process; to utilize, as raw materials, scrap'metal or more or less crude or impure metal.

In carrying out the process, use maybe 1 made of apparatus such as is illustrated d 1agrammatically in the accompanying drawing in which: I

Fig. 1 illustrates a complete "apparatus in side elevation but showing a container 1n longitudinal section, and Fig, 2 a transverse vertical section through said container -in an axial plane of a drum serving as anelectrode. The process involves an electroplating step which consists, generically, in plating wlth metal upon a metallic chromium or chromium containing surface from which the platmg may be afterwards stripped. The chrom um or chromium containing surface may be on the periphery of a drum mounted to rotate, partially submerged, in an electrolyte. By establishing an electric circuit through the chromium bearing surface of said drum, which thus serves as one' electrode, and submerging in the electrolyte other electrodes formed of or containing the metal of which the desired strip or shell is composed, a deposit of the metal of the latter electrodes wlll collect on the metallic periphery of the drum. The layer of metaldeposited on the periphery of the drum may be readily peeled or stripped therefrom. The material of the electrodes composed of metal of which the sheet is to be formed will be continuously transferred to that portion of the perihphery of the drum that is submerged in the electrolyte, and may be continuously stripped from that portion of the drum that is above the electrolyte. The strip so being separated from the drum may be passed through a cleaning solution, then subjected to the action of a drying device, then have its edges sheared or trimmed by drawing between rolls having shearing disks and then smoothed,

compacted and drawn from the drum by pressure rolls, whence it may pass to a winding reel or spool.

In the drawings, 10 indicates a container for an electrolyte 11 and 12 a container for a cleansing liquid 13. In the illustrated embodiment these containers are combined in one tank divided into two chambers by a transverse partition 14. A rotary electrode in the form of a drum 15 is mounted so that its lower portion may dip into the electrolyte 11. Other electrodes 16, containing a metal to be plated upon the drum 15, are suspended .in the electrolyte. Leads 17 connect electrodes'16 with a source of electrical energy and a lead 18 connects the drum 15 therewith. Electrodes 16 are anodes and drum electrode 15 is a cathode in the equipment shown. A guide, preferably a roller 19, is disposed above one end of the chamber containing the cleansing liquid 13 and a guide, such as roller 20, above the opposite end. A stripper, such as a roller 21, is disposed adjacent the drum. Submerged-in the cleansing liquid are other guides, such as rollers 22. A reel or winding spool 23 is located some distance from the guide 20 and between said reel or spool and said guide 20 are drying means, such as air nozzles 24, trimming devices 25, and one or more pairs of pressure rolls 26. The drying means are preferably between the guide 20 and the trimming means 25; the pressure rolls between the trimming means and the reel or winding spool. The drum, stripper, guides, drying means, trimmlng means, pressure rolls and winding spool are arranged in series order, in such position that a strip drawn by the pressure rolls and winding spoolfrom the drum 15 will move between parallel planes as directly as practicable from the drum to the spool. The active surface of the stripper 21 is disposed on that slde of a plane, tangent to the active surface of guide 19 and unsubmerged perimeter of drum 15, that is away from the drum 011, in the illustrative equipment, above that p ane. a

Drum 15 may be mounted on a shaft 27 rotatable in bearings 28 mounted on the sides of container 10 w1th its axis parallel with the axis of the winding spool 23 and the several guides referred to. Drum hasv a pcriphery of chromium or chromium containing metal. It may be made entirely of chromium or chromium containing metal, and in any event all exposed parts that dip below the surface of the electrolyte except the periphery should have a surface that cannot be plated. Drums made entirely of metal are intended to be covered with a substance that prevents the electrodeposition of metal except upon the expose periphery. In the drawing the entire drum except the perimeter.

hub and rim. The plating, or receiving surface for the deposited metal, is the smooth surface of revolution 33 not covered by .the

the container 12. Electric current is then discoating 29.

The plating surface 33 may be formed on a body of pure metallic chromium, as by cast-V ing a drum of chromium and machinin the perimeter; or the central and main bo y of the drum may be formed of other metal, or other suitable material, and a thin layer of chromium plated or otherwise formed upon the periphery.

A pure metallic chromium surface is not essential. It has been found by extensive experiments that plating surfaces of ferrous .alloys containing substantial proportions of the chromium are effective. Plating surfaces on ferrous alloys having as low as 10% chromium have afforded good results, and plating surfaces formed on ferrous alloys containing any proportion of chromium from 10% upward can be used. In making thin strips of copper, for example, by this process, a plating surface on a ferrous alloy containing 20% chromium collects satisfactorily a plating of copper which can be stripped with facility, and the sheets of copper so formed have possessed excellent physical properties. Extensive experiments have led to the conclusion that any of the metals may be formed into thin sheets by this process. Sheets of copper, nickel, zinc, brass and others of the more common metals have been made in this manner.

In practising this processby the aid of the apparatus conventionally illustrated the procedure is as follows:

Electrodes 16 composed substantially of the metal to be formed into sheets or strips are suspended in a suitable electrolyte 11 in charged from the electrodes 16 to the 'exposed plating surface 33 of the drum 15,

. while the latter is being rotated in the diincome rection indicated by the arrow in Fig. 1.

When the drum has rotated far enough to bring'the coating 35 of plating metal deosited thereon to the top this coating may be ifted from the drum, as by the aid of any thin edged instrument and peeled and strip-- 19, under guides 22, over guide 20, between drying nozzles 24, trimming means 25, pressmg rolls 26, and attached to spool 23 in'such manner that rotation of the spool will tension the sheet and wind it thereon as the sheet is stripped from the drum, washed in the contalner 12, dried by an air blast/issuing from nozzles 24, edge trimmed by the trimming means 25 and drawn, flattened, reduced or compacted by the pressure rolls 26, all in one continu ng operation. It will be apparent that, with an apparatus of the kind illustrated, theoperation may proceed indefinitely and strips of indefinite length be produced, as it 1s an easy matter to insert new electrodes 16 at any time when one or more is nearly or partly consumed.

What is claimed is as follows:

1 The process of producing sheets of metal whlch comprises electrodepositing the metal dlrectly upon a chromium contaimng metallic surface and stripping the sheet so formed from said surface.

2. The process of producing sheets of copper which comprises electrodepositing the copper directly upon a chromium containing metallic surface and stripping the sheet so formed from said surface. 4

In testimony whereof we hereto afiix our signatures.

HARRY M. WILLIAMS. ROBERT G. SUMAN. 

